title: An atypical form of Bietti crystalline dystrophy.
abstract: OBJECTIVE
  To describe clinical and functional features of a patient with Bietti crystalline dystrophy and atypical electroretinogram responses.
  
  
  METHODS
  The patient underwent a thorough medical anamnesis, genetic counseling, peripheral blood draw for CYP4V2 gene analysis and electron microscopy, and a complete ophthalmological assessment including optical coherence tomography, indocyanine green angiography, microperimetry, full-field electroretinogram and multifocal electroretinogram.
  
  
  RESULTS
  The most striking features of the retina were deposits of yellowish-white glistening crystals and focal lobular areas of choriocapillary atrophy at the posterior pole and midperiphery. The full-field electroretinogram was normal and the multifocal electroretinogram showed extinguished central recordings. Mutation analysis revealed a homozygous c. 332T>C p.I111T mutation in exon 3 of the CYP4V2 gene. Typical cytoplasmic inclusions containing crystalline-like structure and large degenerative lysosomes were seen on electron microscopy of peripheral leukocytes.
  
  
  CONCLUSIONS
  Here we describe a patient with Bietti crystalline dystrophy with a CYP4V2 gene mutation and typical leukocyte inclusions who showed the classical retinal lesions but had a normal electroretinogram. This suggests the existence of less severe forms of BCD related to relatively mild CYP4V2 mutations.
authors.affiliation: Department of Ophthalmology, Second University of Naples, Napoli, Italy.
authors.forename: Settimio
authors.initials: S
authors.lastname: Rossi
authors.forename: Francesco
authors.initials: F
authors.lastname: Testa
authors.forename: Anren
authors.initials: A
authors.lastname: Li
authors.forename: Valentina Di
authors.initials: VD
authors.lastname: Iorio
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Carlo
authors.initials: C
authors.lastname: Gesualdo
authors.forename: Michele Della
authors.initials: MD
authors.lastname: Corte
authors.forename: Chi-Chao
authors.initials: CC
authors.lastname: Chan
authors.forename: J
authors.initials: J
authors.lastname: Fielding Hejtmancik
authors.forename: Francesca
authors.initials: F
authors.lastname: Simonelli
mesh_terms: D003317:Corneal Dystrophies, Hereditary / Q000175:diagnosis / Q000235:genetics; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D000072470:Cytochrome P450 Family 4; D004252:DNA Mutational Analysis; D004596:Electroretinography; D005451:Fluorescein Angiography; D006801:Humans; D002479:Inclusion Bodies / Q000235:genetics / Q000473:pathology; D007208:Indocyanine Green; D007962:Leukocytes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009755:Night Blindness / Q000175:diagnosis / Q000235:genetics; D010375:Pedigree; D012164:Retinal Diseases / Q000175:diagnosis / Q000235:genetics; D055213:Retinal Pigment Epithelium / Q000473:pathology; D041623:Tomography, Optical Coherence; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology
chemical_list: D003577:Cytochrome P-450 Enzyme System; C505357:CYP4V2 protein, human; D000072470:Cytochrome P450 Family 4; D007208:Indocyanine Green